So far, little research has been conducted into developing a QAPM (Quality Assurance Process Model) for telecommunications applications on the basis of TMN. This is the first trial of the design of TMN-based QAPM on fault management with UML. A key attribute of the QAPM is that it can easily identify current deficiencies in a legacy system on the basis of TMN architecture. Using an empirical comparison with the legacy systems of a common carrier validates the QAPM as the framework for a future mode of the operation process. The results indicate that this paper can be used to build ERP(Enterprise Resource Planning) for a telecommunications fault management solution that is one of the network management application building blocks. The future work of this paper will involve applying the QAPM to build ERP for RTE (Real Time Enterprise) fault management solution and more research on ERP design will be necessary to accomplish software reuse.